1. Field of the Invention
The present invention relates to a coupling device used when connecting a tube to a container containing liquid or the like.
2. Description of the Related Art
Conventionally, in order to take out the liquid that is stored inside a container, a gas (air or the like) is introduced inside the container and the liquid is forced outside the container by the pressure of the gas.
If the liquid is one that cannot be allowed to come into contact with a gas, an internal bag is placed inside the container and the liquid is kept sealed inside that bag. To take out the liquid, air is introduced to the outside of the internal bag thereby shrinking the bag with the resulting pressure and forcing out the liquid.
However, in the above examples, because it is necessary for a tube for extracting the liquid and a tube for introducing the gas to both be connected to the container, and for main flow passages and sub flow passages to be coupled, the work efficiency tends to deteriorate.
Accordingly, the aim of the present invention is to provide a coupling device that achieves an improvement in the work efficiency by allowing the simple coupling of different types of liquid flow passages.